Power generation and battery management systems

ABSTRACT

The disclosed power system may comprise first and second batteries; an electrical power generator; an electrical load powered by at least one of the first battery, the second battery or the electrical power generator; a converter; and a battery management controller. The converter is connected to both the first and second batteries and configured to operate in a neutral mode, a first battery charging mode, or a second battery charging mode. The converter is configured to create a voltage difference between the first and second batteries in the charging modes. The battery management controller is configured to monitor the voltage of the first battery and the voltage of the second battery and/or to monitor current flow to and from the first and second batteries. The controller controls operation of the converter to operate in the neutral mode, the first battery charging mode or the second battery charging mode.

This application is a continuation-in-part of U.S. patent applicationSer. No. 11/560,160 filed on Nov. 15, 2006, which is incorporated byreference herein in its entirety.

BACKGROUND

The present invention relates to a battery management controller to beused with a power generation system in a vehicle.

One example of a power generation system that could benefit from thedisclosed battery management controller is a truck HVAC system. However,the present invention is not limited to truck HVAC systems and thereference herein to such a system is for exemplary purposes only.

Truck drivers that move goods across the country may be required to pullover at various times along their journey so as to rest so that they donot become too fatigued. Common places for truck drivers to rest includerest stops, toll plazas, and the like. However, these locations usuallydo not have any accommodations for the drivers, and as a result theyusually remain inside the cab of the truck inside a sleepingcompartment. To provide the driver with maximum comfort, the sleepingcompartment should be temperature controlled so that the environment inthe truck is conducive for the driver to get the rest he or she needs.

Currently, trucks tend to use engine-belt driven compressors for the airconditioning system to circulate and pump refrigerant throughout thevehicle to cool the driving compartments. In addition, an engine-beltdriven pump may circulate engine waste heat throughout the drivingcompartments when heating is required. Unfortunately, these systems havethe drawback of not being able to operate when the engine is turned off.As a result, the driver has the choice of either keeping the enginerunning (which requires additional fuel) so as to run the temperaturecontrol system or turning the engine off and not using the airconditioning or heating systems (which may make the driveruncomfortable).

SUMMARY

According to one embodiment of the present invention, a power system tobe installed in a vehicle may comprise a first battery having a firstbattery voltage; a second battery having a second battery voltage; anelectrical power generator configured to charge the first battery; anelectrical load powered by at least one of the first battery, the secondbattery or the electrical power generator; a converter; and a batterymanagement controller. The converter is connected to both the first andsecond batteries and configured to operate in either a neutral mode or afirst battery charging mode or a second battery charging mode. Theconverter is configured to create a voltage difference between the firstand second batteries in the charging modes. The battery managementcontroller is configured to monitor the first voltage of the firstbattery and the second voltage of the second battery and/or to monitorthe current flow to and from the first and second batteries. Thecontroller controls the operation of the converter to operate in eitherthe neutral mode, the first battery charging mode or the second batterycharging mode. In the second battery charging mode, the converter isconfigured to adjust the voltage difference between the first batteryand the second battery to cause current to flow from the first batteryto the second battery to thereby charge the second battery.

According to another embodiment of the present invention, a vehiclepower system may comprise an electrical generator driven by an engine ofa vehicle; a main battery connected to a secondary battery for supplyingcurrent to an electrical load; and a controller. The controller iscoupled to the main battery and the secondary battery. The controller isconfigured to adjust the system so that the main battery is charged bythe secondary battery when a state of charge of the main battery isbelow a predetermined threshold even when a state of charge of thesecondary battery is less than the state of charge of the main battery.

According to another embodiment of the present invention, a vehicle maycomprise: an interior area including a driver compartment and a sleepercompartment; an interior subsystem comprising a blower and anevaporator; an exterior subsystem; and a liquid phase cooler. Theexterior subsystem may comprise a compressor and a condenser, whereinthe exterior subsystem is mounted to a location outside the interiorarea. The interior subsystem may be mounted within the interior area andbe operably connected with the exterior subsystem. The liquid phasecooler may comprise an outer tube with two first connectors and an innertube with two second connectors, wherein the inner tube is placed withinthe outer tube.

According to another embodiment of the present invention, an airconditioning system for use in an over-the-road vehicle may comprise: avariable-speed compressor for providing refrigerant to a heat exchangerpositioned to provide temperature control to an interior compartment ofa vehicle; a brushless DC motor operably coupled to the variable-speedcompressor; an evaporator; and an controller operably coupled to themotor. The controller may receive electric power from at least onesource of electric power operable when an engine of the vehicle is notoperating. The controller may modulate compressor speed of thecompressor such that the evaporator is maintained at a predeterminedevaporator temperature.

It is to be understood that both the foregoing general description andthe following detailed description are exemplary and explanatory only,and are not restrictive of the invention as claimed.

BRIEF DESCRIPTION OF THE DRAWINGS

The features, aspects and advantages of the present invention willbecome apparent from the following description, appended claims, and theaccompanying exemplary embodiments shown in the drawings, which arebriefly described below.

FIG. 1 is a schematic diagram of an HVAC system to be installed in avehicle.

FIG. 2 is a schematic diagram of an HVAC system according to anotherexemplary embodiment.

FIG. 3 is a schematic diagram of an alternative configuration of theHVAC system of FIG. 2.

FIG. 4 is a schematic diagram of an HVAC system according to anotherexemplary embodiment.

FIG. 5 is a schematic diagram of a power system according to anembodiment of the present invention.

FIG. 6( a) is flow chart showing the operation of the power systemduring an accessory run mode.

FIG. 6( b) is flow chart showing the operation of the power systemduring an engine start mode.

FIG. 6( c) is a flow chart showing the operation of the power systemduring a recharging mode.

FIG. 7 shows a schematic diagram of a power system according to anotherembodiment of the present invention.

FIG. 8 shows a schematic diagram of a power system according to anotherembodiment of the present invention.

FIG. 9 shows a schematic diagram of a power system according to anotherembodiment of the present invention.

FIG. 10 shows a schematic diagram of a power system according to anotherembodiment of the present invention.

FIG. 11 is a schematic diagram of a HVAC component controller.

FIG. 12 is a flow chart showing the operation of the HVAC componentcontroller.

FIG. 13 is a schematic diagram of an HVAC system to be installed in avehicle.

FIG. 14 is a power generation system including a battery managementcontroller.

FIG. 15 is a liquid phase cooler connecting the interior and exteriorsubsystems of FIG. 13.

FIG. 16( a) is a perspective frontal view of low-loss quick connectorsfor connecting the liquid phase cooler according to an embodiment of thepresent invention.

FIG. 16( b) is a perspective frontal view of one-time quick connectorsfor connecting the liquid phase cooler according to an embodiment of thepresent invention.

DETAILED DESCRIPTION

Hereinafter, various embodiments of the present invention will bedescribed in detail with reference to the drawings.

FIG. 1 is a schematic diagram of an HVAC system to be installed in avehicle according to an embodiment of the present invention. The HVACsystem 10 may comprise a motor 12, a compressor 14, circulation blowers210 and 212, an HVAC component controller 50, and a power system 70. Themotor may be operatively coupled to the compressor 14. The compressor 14is a stepless continuously variable speed compressor, which is driven bythe motor 12. The compressor 14 circulates refrigerant through thecondenser 16 to an optional refrigerant receiver and dryer 18. From therefrigerant receiver and dryer 18, the refrigerant then passes to eithera first cooling path 21 that cools the driving compartment 23 or asecond cooling path 25 that cools the sleeping compartment 27 of thevehicle. As to the first cooling path 21, the refrigerant passes througha refrigerant metering device 20 and an evaporator 22. The refrigerantmetering device 20 may or may not be an expansion device, such as athermostatic expansion valve, a pressure control expansion valve, acapillary tube, or the like, used in the conventional way. In onearrangement, the refrigerant metering device 20 is a metering devicefeeding refrigerant into the flooded evaporator 22 with no expansiontaking place at or near the valve 20, and thus merely meters in liquidrefrigerant at a rate sufficient to maintain the correct liquid level inthe evaporator. Air is blown over the evaporator 22 by the circulationblower 210. After the air is cooled by the evaporator 22, the airproceeds through an air duct 272 towards the driving compartment 23 ofthe vehicle.

A second cooling path 25 runs parallel to the first cooling path 21 inwhich the refrigerant is provided through a refrigerant metering device24 and an evaporator 26. Air is blown over the evaporator 26 by acirculation blower 212. After the air is cooled by the evaporator 26,the air proceeds through an air duct 276 towards the sleepingcompartment 27 of the vehicle. The evaporator 26 of the second coolingpath 25 may be smaller than the evaporator 22 of the first cooling path21 because the sleeping compartment 27 is typically smaller than thedriving compartment 23.

The two coolant loops may be selectable through the use of valves 28 and29. The inclusion of such valves permits the driving compartment 23, thesleeping compartment 27, or both compartments to be air conditioned at aparticular time. The valves 28 and 29 may be controlled through the HVACcomponent controller 50 (to be discussed below). Once the refrigerantpasses through the evaporator 22 and/or 26, the refrigerant then passesthrough an optional refrigerant accumulator 30 before being returned tothe compressor 14 to restart the process.

The motor 12 may be any suitable motor. For example, the motor 12 may bea brushless DC motor that is commutated by a square or trapezoidal waveform. In another example, the motor 12 may be a synchronous permanentmagnet motor that is commutated with a sine wave. When the motor isdriven by a sine wave, additional benefits may be obtained, such asbetter drive efficiency, better cooling and quieter operation.

By using a variable speed compressor 14 driven by a brushless DC or asynchronous permanent magnet motor 12, the vehicle's HVAC system may beoperated when the engine is turned on or when the engine is turned off.The variable speed compressor 14 also may permit the HVAC system 10 tooperate at a lower capacity during the engine off operation to conservethe amount of stored energy available for usage by the system 10. Thecontrol for this operation is provided by a HVAC component controller 50that monitors various system parameters while a battery managementcontroller 60 monitors the availability and status of the power sourceson the vehicle and provides power to the HVAC system. The power sourcesand battery management controller 60 are part of a power system 70, asseen in FIG. 5. As will be described in more detail later, the powersystem 70 seen in FIG. 5 may have as its power sources a first powersource 40, a second power source 42, and/or the vehicle's mainelectrical power generation system 44.

In a similar manner, the circulation blowers 210 and 212 may also havestepless continuously variable speeds such that the circulation blowersmay operate at a lower capacity during the engine off operation toconserve the amount of stored energy available for usage by the HVACsystem 10. The control for this operation is also provided by the HVACcomponent controller 50.

The battery management controller 60 is configured such that thevehicle's HVAC system 10 is capable of being powered by the vehicle'smain electrical power generation system 44, which is available while thevehicle's engine is operating. When the vehicle's engine is off, theHVAC system 10 may be powered with a first power source 40 and/or asecond power source 42 depending on the power levels of the powersources (as will be described later). In one embodiment, the first powersource 40 may be the vehicle's one or more starter batteries while thesecond power source 42 may be one or more auxiliary deep-cyclebatteries.

In the HVAC system 10, the motor driven compressor 14 may have theability to modulate its output from full capacity to low capacity. Thisability to modulate allows the use of a single HVAC system that may beused for both high output for the time periods that the engine isoperating, and low output during the time periods when the engine isturned off so as to continue to cool or heat the driving and/or sleepingcompartments. The coordination of this modulation is provided by theHVAC component controller 50, which reduces the speed of the compressorwhen the engine is turned off. This modulation extends the duration ofthe heating and cooling operations because the charge of the availablepower sources is expended more slowly. That is, with a reduced speed ofthe compressor, the electric power demand is reduced as well.

Another aspect of FIG. 1 is a heating mode of operation in which thereis an air heater in each air duct that leads to the vehiclecompartments. For example, the air heater 270 is disposed in the airduct 272 which leads to the driving compartment 23. The air heater 274is disposed in the air duct 276 which leads to the sleeping compartment27. The air heaters 270 and 274 may be any heater known in the art, suchas an electric resistance-type heater. The advantage of using anelectric resistance-type heater is that such a heater allows the heatingfunction to be completed without relying on the engine or additionalfuel by merely relying on the circulation blowers and the heaters, whichare powered by the first and/or second power sources or the vehicleelectrical power generation system. In a preferred embodiment, insteadof the air ducts 272 and 276, the air heaters 270 and 274 may be placedwithin the same enclosures as the circulation blowers 210 and 212 butstill in the path of the gas stream which enters the vehicle and/orsleeping compartments. If the air heaters are in the same enclosures asthe circulation blowers, there may be a reduction in the complexity ofthe installation.

To operate in the heating mode, the HVAC component controller 50 doesnot operate the compressor 14 but merely operates the circulation blower210 and the air heater 270 to provide the necessary heating to thedriving compartment and/or the circulation blower 212 and the air heater274 to provide the necessary heating to the sleeping compartment. Thisconfiguration provides additional power consumption savings and allowsfor a longer operating duration in the heating mode. In the cooling modeof operation, the air heaters 270 and 274 are simply not activated. Iftemperature control is desired, the HVAC component controller 50 maypreferably provide pulse width modulation control (PWM) of power to theair heaters 270 and 274. Alternatively, temperature control may beperformed by a control door known in the art (not shown) placed in eachduct (if provided) to control the flow of air (which may or may not becooled by the evaporators 22 and/or 26) passing over the air heaters 270and/or 274 to regulate the temperature of the air flowing into theirrespective vehicle compartments.

The embodiment of FIG. 1 may include alternative configurations. Forexample, the first or second cooling path may be eliminated such thatthere is only one expansion device, one evaporator, one blower, and noaccumulator 30. With this configuration only one vehicle compartment maybe temperature controlled. Alternatively, ducting may be used to channelthe temperature controlled air into separate channels in which a firstchannel goes to the driving compartment and a second channel goes to thesleeping compartment. In this embodiment, a control door or the like maybe used to channel the temperature controlled air to one compartment tothe exclusion of the other.

FIG. 2 is a schematic diagram of another embodiment of the HVAC system10 according to another embodiment of the present invention. The HVACsystem 10 of this embodiment includes a primary coolant loop 170 thatincludes a first refrigerant and a secondary coolant loop 172 thatincludes a second refrigerant. The first refrigerant in the primarycoolant loop 170 is driven by the compressor 14 which passes through thecondenser 16, the receiver and dryer 18, the refrigerant metering device20, the first refrigerant-to-second refrigerant heat exchanger 174, andback to the compressor 14.

In contrast, the second refrigerant in the secondary coolant loop 172 isdriven by a low pressure liquid pump 176. The fluid passes through asecond refrigerant-to-air heat exchanger 178, a heater 180, and thefirst refrigerant-to-second refrigerant heat exchanger 174. The firstrefrigerant-to-second refrigerant heat exchanger 174 serves as the heatexchange medium between the primary coolant loop 170 and the secondarycoolant loop 172. The second refrigerant-to-air heat exchanger 178 coolsthe air supplied by the circulation blower 210, which then flows to thevehicle compartment with or without ducting. To provide heating of thevehicle compartment, the HVAC component controller 50 need only operatethe low pressure liquid pump 176 and the heater 180 in the secondarycoolant loop 172 and the circulation blower 210. That is, no power isdelivered to the compressor 14, and as a result the amount of powerconsumption is further reduced, which extends the time duration thatheating may take place.

FIG. 3 shows an alternative configuration of FIG. 2 in which there aretwo second refrigerant-to-air heat exchangers 178 and 182 in thesecondary coolant loop 172. One second refrigerant-to-air heat exchanger178 may be used to provide cooling/heating to the driving compartment 23while the other heat exchanger 180 may be used to providecooling/heating to the sleeping compartment 27 with or without ducting.The passage of the liquid through either or both of the heat exchangers178 and 182 may be selected by the HVAC component controller 50, which,in turn, controls the valve 184 that leads to the heat exchanger 180 andthe valve 186 that leads to the heat exchanger 178. Thus, the control ofthe valves 184 and 186 permits the driving compartment 23, the sleepingcompartment 25, or both compartments to be air conditioned or heated ata particular time.

FIG. 4 shows another embodiment of the present invention in which theHVAC system uses a reverse cycle heating system. The reverse cycleheating system also allows the heating function to be completed withoutrelying on the engine or additional fuel by merely relying on thecompressor and the circulation blowers, which are powered by the firstand/or second power sources or the vehicle electrical power generationsystem. As with the embodiment shown in FIG. 1, the HVAC system 10 ofFIG. 4 may comprise a motor 12, a compressor 14, circulation blowers 210and 212, an HVAC component controller 50, and a power system 70. Themotor may be a brushless DC or a synchronous permanent magnet motor,which is operatively coupled to the compressor 14. The compressor 14 isa continuously variable speed compressor, which is driven by the motor12. Connected to the compressor is a reversing valve 502, which allowsthe compressor to pump refrigerant in a cooling direction indicated bysingle arrows 520 or a heating direction indicated by double arrows 522.

As to the cooling direction, the compressor 14 circulates refrigerantthrough a heat exchanger 504 (which functions as a condenser in thecooling mode as the hot compressed gas from the compressor condenses toa liquid as heat is given off) to a first flow path 510 that thermallytreats air going to the driving compartment 23 and/or a second flow path512 that thermally treats air going to the sleeping compartment 27 ofthe vehicle. As to the first flow path 510, the refrigerant passesthrough a refrigerant metering device 20 and a heat exchanger 506 (whichfunctions as an evaporator in the cooling mode as the liquid refrigerantboils and forms a gas as heat is absorbed by the refrigerant liquid).Air is blown over the heat exchanger 506 by the circulation blower 210.After the air is cooled by the heat exchanger 506, the air proceedstowards the driving compartment 23 of the vehicle.

A second flow path 512 runs parallel to the first flow path 510 in whichthe refrigerant is provided through a refrigerant metering device 24 anda heat exchanger 508 (which functions as an evaporator during thecooling mode as the liquid refrigerant boils and forms a gas as heat isabsorbed by the refrigerant liquid). Air is blown over the heatexchanger 508 by a circulation blower 212. After the air is cooled bythe heat exchanger 508, the air proceeds towards the sleepingcompartment 27 of the vehicle. The heat exchanger 508 of the second flowpath 512 may be smaller than the heat exchanger 506 of the first flowpath 510 because the sleeping compartment 27 is typically smaller thanthe driving compartment 23.

The two coolant loops may be selectable through the use of valves 28,29, 514, and 516. The inclusion of such valves permits the drivingcompartment 23, the sleeping compartment 25, or both compartments to beair conditioned at a particular time. The valves 28 and 514 are openedand the valves 29 and 516 are closed when only the driving compartmentis being temperature controlled. By a similar token the valves 29 and516 are opened and the valves 28 and 514 are closed when only thesleeping compartment is being temperature controlled. The valves 28, 29,514, and 516 may be controlled through the HVAC component controller 50.Once the refrigerant passes through the heat exchanger 506 and/or 508,the refrigerant then returns to the reversing valve 502 and thecompressor 14 to restart the process.

As to the heating direction, the reversing valve 502 is switched suchthat the refrigerant pumped by the compressor flows in the reversedirection as indicated by double arrows 522. Thus, the compressor causesthe refrigerant to flow through the first flow path 510 and/or thesecond flow path 512 depending if the valves 28 and 514 and the valves29 and 516 are opened or closed. If the valves 28 and 514 are opened,the refrigerant flows through the heat exchanger 506 (which functions asa condenser in the heating mode as the hot gas is condensed to a liquidas it gives up heat). Air is blown over the heat exchanger 506 by thecirculation blower 210. After the air is heated by the heat exchanger506, the air proceeds towards the driving compartment 23 of the vehicle.Meanwhile, the refrigerant continues from the heat exchanger 506 throughthe refrigerant metering device 20 to the heat exchanger 504 (whichfunctions as an evaporator in the heating mode). After flowing throughthe heat exchanger 504, the refrigerant returns to the reversing valve502 and the compressor 14.

If the valves 29 and 516 are opened, the refrigerant flows through theheat exchanger 508 (which functions as a condenser in the heating mode).Air is blown over the heat exchanger 508 by a circulation blower 212.After the air is heated by the heat exchanger 508, the air proceedstowards the sleeping compartment 27 of the vehicle. Meanwhile, therefrigerant continues from the heat exchanger 506 through therefrigerant metering device 24 to the heat exchanger 504 (whichfunctions as an evaporator in the heating mode). After flowing throughthe heat exchanger 504, the refrigerant returns to the reversing valve502 and the compressor 14 to restart the process.

Similar to the embodiment shown in FIG. 1, the embodiment of FIG. 4 mayinclude a variable speed compressor 14 driven by a brushless DC or asynchronous permanent magnet motor 12; the control for the heating andcooling operations being provided by the HVAC component controller 50.The available power sources may come from the power system 70, which mayinclude a first power source 40, a second power source 42, and/or thevehicle's main electrical power generation system 44 as seen in FIG. 5.The circulation blowers 210 and 212 may also have continuously variablespeed which may be controlled by the HVAC component controller 50; andthe battery management controller 60 of the power system 70 may monitorand control the available power sources when the engine is turned off.

Also as with the embodiment of FIG. 1, FIG. 4 may include alternativeconfigurations. For example, the first or the second cooling path may beeliminated such that there is only one refrigerant metering device, oneheat exchanger in which air passes over, and one blower. With thisconfiguration only one vehicle compartment may be temperaturecontrolled. Alternatively, ducting may be used in which the ductchanneling the temperature controlled air may be spit into multiplechannels such that a first channel goes to the driving compartment and asecond channel goes to the sleeping compartment. In this embodiment, acontrol door or the like may be used to channel the temperaturecontrolled air to one compartment to the exclusion of the other.

The power requirements and operation of the HVAC system 10 are handledby the battery management controller 60 of the power system 70 and theHVAC component controller 50, respectively. The two controllers 50 and60 may be software control loops with associated hardware or circuitry,and they may be physically housed in separate devices or the samedevice.

The power system 70 with the battery management controller 60 will nowbe discussed with reference to FIG. 5. The power system 70 may comprisea first power source or battery 40, a second power source or battery 42,an electrical power generator 76 in an electrical generation system 44,an electrical load 78; a first regulator or converter 72, a secondregulator 73, a third regulator 74, a user interface 51, and a batterymanagement controller 60. The first regulator or converter 72, thesecond regulator 73, the third regulator 74, and the battery managementcontroller 60 may constitute a power management module. The powermanagement module may also include the user interface 51, temperatureand voltage sensors 63, sensors for monitoring current flow to and fromthe first and second power sources, and/or the HVAC component controller50. The components of the power management module may be or may not becontained within a single housing.

In one exemplary embodiment, a truck may have seven batteries in whichfour batteries are connected in parallel to provide a high capacityfirst battery bank as the first power source 40 and the three remainingbatteries are connected in parallel to provide a second, somewhatsmaller battery bank as the second power source 42. For the followingdiscussion, the first power source 40 will be called the first battery(which may be a single battery or a plurality of batteries in a batterybank) and the second power source 42 will be called the second battery(which may be a single battery or a plurality of batteries in a batterybank). The first battery 40 can have a first battery voltage and thesecond battery 42 may have a second battery voltage that is differentfrom the first battery voltage.

The first battery 40 and/or the second battery 42 may be connected tothe first regulator 72, the second regulator 73, and temperature andvoltage sensors 63. Also, one of the first and second batteries is alsoconnected to the vehicle starting system to provide power to start theengine of the vehicle, for example, by being connected to the enginestarter 64. In the embodiment of FIG. 5, the first battery 40 may be,for example, one or more starter batteries which are used to start upthe vehicle upon ignition. Accordingly, the first battery 40 may beconnected to the engine starter 64. According to one embodiment of thepresent invention, the first battery may be a lower quality battery thanthe second battery such that it may not be desirable to discharge thefirst battery to more than 20-30%. Alternatively or additionally, thefirst battery may be a secondary or auxiliary battery while the secondbattery may be the main battery of the vehicle. The second (main)battery can be connected to the first (secondary battery) for supplyingcurrent to the electrical load 78.

The temperature and voltage sensors 63 may monitor the voltage andtemperatures of the first and second batteries 40 and 42. Additionallyor alternatively, sensors for monitoring the current flow to and fromthe first and second batteries may be used. These sensors may be used tomonitor the state of charge of the batteries so as to prevent thebatteries from being overly discharged.

The engine starter 64 is connected to one of the batteries so as toprovide enough power to start the engine of the vehicle. The enginestarter 64 may be electrically directly connected to the first battery,directly connected to the second battery, and/or directly connected toone of the first and second batteries while the other of the first andsecond batteries is connected to the engine starter through the secondregulator or converter 73. In FIG. 5, the engine starter 64, forexample, is directly connected to the first battery 40 and is indirectlyconnected to the second battery 42 via the first battery 40 and thesecond regulator 73.

The electrical power generation system 44 comprises an electrical powergenerator 76 configured to charge the first battery 40, the secondbattery 42, and/or run the electrical load 78. Although the embodimentof FIG. 5 shows that the electrical power generator 76 is not directlyconnected to the load 78, it is contemplated that the generator 76 maybe directly connected to the load 78. In one embodiment, the electricalpower generator 76 is an alternator, such as a truck alternator,configured to be driven by the engine of the vehicle. The alternator maybe configured such that, when the engine is on and running idle, theHVAC system should be able to run at maximum speed and load while thealternator provides maximum charging capacity for the batteries at thesame time. For example, the alternator may be rated for 250 A, 24 V or500 A, 12 V. In such an embodiment, the battery management controller 60is configured to control the excitation of the alternator to control thealternator output voltage.

The first regulator 72 may be a current regulator, which is connected tothe electrical power generator 76 and to at least one of the first andsecond batteries 40 and 42. The battery management controller 60controls the current regulator 72 so as to regulate the amount ofcurrent flowing from the generator 76 to the at least one of the firstand second batteries 40 and 42. According to the embodiment of FIG. 5,the first regulator 72 is connected to both the first and secondbatteries 40 and 42, and thus may be controlled by the batterymanagement controller 60 to regulate the amount of current flowing fromthe generator 76 to both the first and second batteries. In other words,the first regulator 72 may charge up the first battery 40, charge up thesecond battery 42, and/or run the components of the HVAC system 10 basedon commands from the battery management controller 60. The firstregulator 72 may be a DC-to-DC converter, such as a buck DC regulator ora buck/boost DC regulator and selector.

The second regulator 73 may connect the first and second batteries 40and 42 together to control the current flow between the first and secondbatteries. The regulator 73 may be a DC-to-DC converter, such as abuck/boost DC regulator and selector. The second regulator 73 may be aconverter that is controlled by the battery management controller 60 tooperate in a neutral mode, a first battery charging mode, or a secondbattery charging mode. In the first and second battery charging modes,the second regulator or converter 73 is configured to create a voltagedifference between the first and second batteries. For example, in thefirst battery charging mode, the second regulator 73 is configured toadjust a voltage difference between the first and second batteries so asto cause current to flow from the second battery to the first battery tothereby charge the first battery, regardless of the respective chargesof the two batteries. That is, current can flow from the second batteryto the first battery even if the first battery may have a charge that isgreater than, equal to, or less than the charge of the second battery.Thus, the battery management controller 60 coupled to the first andsecond batteries (for example, secondary and main batteries,respectively) is configured to adjust the system so that the first(secondary) battery is charged by the second (main) battery when a stateof charge of the first (secondary) battery is below a predeterminedthreshold even when a state of charge of the second (main) battery isless than the state of charge of the first (secondary) battery.

In the second battery charging mode, the second regulator 73 isconfigured to adjust the voltage difference between the first batteryand the second battery so as to cause current to flow from the firstbattery to the second battery to thereby charge the second battery,regardless of the respective charges of the two batteries. That is,current can flow from the first battery to the second battery even ifthe second battery may have a charge that is greater than, equal to, orless than the charge of the first battery. Thus, the battery managementcontroller 60 coupled to the first and second batteries (for example,secondary and main batteries, respectively) is configured to adjust thesystem so that the second (main) battery is charged by the first(secondary) battery when a state of charge of the second (main) batteryis below a predetermined threshold even when a state of charge of thefirst (secondary) battery is less than the state of charge of the second(main) battery.

In the neutral mode, the second regulator 73 is configured so that nocurrent flows between the first and second batteries. For example, thebattery management controller 60 may be configured to operate the secondregulator 73 in the neutral mode so as to break the connection betweenthe first and second batteries to prevent current from flowing betweenthe two. Alternatively, the battery management controller 60 may beconfigured to operate the second regulator 73 in the neutral mode so asto adjust the voltage difference between the first and second batteriesto prevent current from flowing between the first and second batteries.

The third regulator 74 may be a boost DC regulator connected to at leastone of the first and second batteries 40 and 42 and to the load 78 (forexample, one or more components of the HVAC system 10). The boostconverter raises the voltage being supplied to the load by the at leastone of the first and second batteries 40 and 42. In the embodiment ofFIG. 5, the boost converter 74 is connected between the second battery42 and the load 78. Thus, the boost converter of FIG. 5 raises thevoltage being supplied to the load by the second battery 42.

The electrical load 78 may be powered by at least one of the firstbattery 40, the second battery 42, and/or the electrical generator 76.The load 78 may be components of the HVAC system 10 for either heatingor cooling the compartment of the vehicle and/or other electrical poweraccessories, such as microwave ovens, televisions, stereos,refrigerators, etc.

The battery management controller 60 provides the following functions:(1) to monitor the first voltage of the first battery 40 and the secondvoltage of the second battery 42 and/or to monitor current flow to andfrom the first and second batteries 40 and 42; (2) to control theoperation of the second regulator or converter 73 to operate in eitherthe neutral mode, the first battery charging mode or the second batterycharging mode; (3) to control the first or current regulator 72 and thesecond regulator or converter to adjust the relative charging rates ofthe first and second batteries; (4) to control the third regulator orboost converter 74 to adjust the power being supplied to the load 78from the at least one of the first and second batteries 40 and 42; (5)to control the power system 70 to conduct an equalization charge of oneof the first (secondary) battery and the second (main) battery using theother of the first and second batteries; (6) to control the electricalgenerator to raise an output voltage to an increased value greater thana normal output voltage in order to conduct an equalization charge onone of the first (secondary) battery and the second (main) battery;and/or (7) to control the first or current regulator 72 so as toincrease the amount of current flowing from the generator to the one ofthe first (secondary) battery and the second (main) battery.

The battery management controller 60 may also fulfill a variety of otherdifferent purposes including: (1) maximizing the electrical poweravailable for use by the HVAC system; (2) ensuring that sufficientelectrical reserve power is available to start the engine; (3) trackinghistorical use (charge and discharge) of all connected batteries; (4)determining the current state of charge of all connected batteries; (5)determining the current end-of life status of all connected batteriesirrespective of their respective charge level; (6) ensuring that thecharge and discharge cycles of all connected batteries are consistentwith the user's preferred compromise between battery longevity andavailable stored energy; and (7) preventing the overloading of thebattery charging system.

The battery management controller 60 may comprise a control logiccircuit 66 and a memory 67. The battery management controller 60 carriesout its function by being connected to the voltage and temperaturesensors 63, the first regulator 72, the second regulator 73, the thirdregulator 74, the electrical power generation system 44, a userinterface 51 (which may comprise a display 310 and one or more inputdevices 312), and the HVAC component controller 50.

The memory 67 of the battery management controller may be any suitablestorage medium, such as a ROM, a RAM, an EEPROM, etc. The memory 67 isused to store a plurality of data to be utilized by the batterymanagement controller 60 when controlling the components of the powersystem 70. For example, the memory 67 may be used to log historical dataobtained during previous charge and discharge cycles, such as voltageand temperature levels, and use the historical data to modify thepermitted depth of discharge to ensure the completeness of future chargecycles. For example, to ensure that the batteries are fully rechargedbetween cycles to prevent premature sulfation and destruction of thebatteries, the battery management controller may monitor and store thetime and power levels of the batteries during the discharge and rechargecycles. This historical data may verify that, in a typical discharge andre-charge cycle, sufficient time and power is available to fullyrecharge the batteries. If there is not sufficient time and power tofully recharge, the control logic circuit 66 may respond by raising theminimum battery cut-off voltages thereby reducing the total amount ofpower which may be drawn from the batteries. In other words, the batterymanagement controller 60 may be configured to be self-learning whichallows the controller to maximize the battery replacement life bymonitoring the first and/or second power sources such that they are notexcessively discharged (i.e., drained) and such that they are notdischarged to a level that does not allow the power source to be fullyrecharged during the typical engine run time. For example, consider thata power source might be a battery in which the battery may be safelydischarged to a level X. Thus, the level X may be the predeterminedamount value during the determination of whether the power source shouldbe connected to the HVAC system. However, if the run cycle of the enginewas too short to allow the battery to fully recharge during the enginerun after the battery had been partially discharged, the battery wouldstill be prematurely destroyed because failure to fully recharge abattery is just as harmful as discharging it too deeply (or draining thecharge too much). To prevent the premature destruction of a battery dueto it not being fully recharged, the battery management controller 60may monitor the battery charge in the power source to determine if thebattery was fully recharged. If the battery was not, then the controller50 may be configured to “learn” during the next operation where thepower source is connected and the engine is turned off such that thebattery should be less deeply discharged, i.e., the battery should bedischarged to a level Y, which is greater than the level X. Then, thelevel Y may be the predetermined amount value during the determinationof whether the power source should be connected to the HVAC system. Inmore simplified terms, if a battery (such as the first battery 40 or thesecond battery 42) can only be recharged at a certain charge rate and ifa user has a tendency to run the engine of the vehicle for an amount oftime shorter than is necessary to fully charge the battery when it isdischarged to a certain level, this information is used by the batterymanagement controller 60 to modify the allowed amount that the batterycan be discharged. Thus, with the modified level of allowed discharge,the battery will be more likely to be fully charged after the engine hasbeen run for that user's typical amount of time.

The memory 67 can also store data that is useful in determining thecurrent state of charge of the batteries. For example, in a moreconventional HVAC system, the measurement of the battery voltage underload is used to determine the state of charge. While this method is lowin cost and easy to implement, it is also highly inaccurate. The voltagemay be used to accurately determine the state of charge but only whensuch measurements are taken in conjunction with temperature and onlyafter the battery has been “at rest” (i.e., unloaded) for a period ortime (typically over one hour). However, the battery managementcontroller 60 of FIG. 5 may use multiple sources of historical data(stored in the memory 67) and real-time data to more accuratelydetermine the current amount of stored energy available for use.Additionally, the battery management controller 60 allows highlyaccurate “resting voltage” measurements of the state of charge to bemade of the power reserve and to be stored even when portions of thebattery power supply are still in use.

The control circuitry 66 of the battery management controller 60 maycomprise the necessary hardware, software, or other mechanisms necessaryto carry out the functions to which it was designed.

The user interface 51 may include a display 310 and input devices 312.The display 310 of the user interface 51 may provide a user, such as avehicle occupant, information related to the status of the HVAC system10 and/or the power system 70. The display may include one or more of analphanumerical display, a graph, or the like. For example, the displaymay include the vehicle's interior ambient temperature, the exteriorambient temperature, the circulation blower speeds, the usage of thepower source or sources supplied to the HVAC system 10, and warningmessages, etc. In one example, if the first power source and the secondpower source are batteries, the display may show the current approximatebattery charges for each power source to the vehicle occupant.

One or more input devices 312 may also be a part of the user interface.The input devices may be one or more of a keyboard, a control panel, orthe like, so that the vehicle occupant may input user preferences forthe operation of the HVAC system 10 and the power system 70. Forexample, the user preferences may include the operating mode of the HVACsystem such as off, heating, and cooling modes of operation. Also, theinput device 312 of the user interface may allow a user, such as avehicle occupant, to select the operating mode of the second regulatoror converter 73, for example, the neutral mode, the first batterycharging mode, or the second battery charging mode.

Below is a discussion of the processes that occur during the accessoryrun mode when the batteries are discharging when in the engine is turnedoff, the engine start-up mode, and recharge mode when the batteries arebeing recharged when the engine is turned on.

The process that the power system including the battery managementcontroller undergoes during an accessory run (discharging) mode isprovided in FIG. 6( a). The discharging of the first and/or secondbatteries occurs when the engine is turned off and an accessory or aplurality of accessories is turned on as shown in step 402. Although theforegoing discussion talks of only one accessory being powered, it isunderstood the same discussion applies to when a plurality ofaccessories are being powered. According to one example the accessorymay be the HVAC system 10 for heating or cooling the compartment of thevehicle. The battery management controller 60 (“BMC”) determines aminimum acceptable state of charge for both batteries based on presetbase limits, historical charge/discharge levels, priority batteryconditions, user inputs, and temperature as shown in step 404. In step406, the battery management controller 60 through its control circuit 66determines the state of charge and condition of the first and secondbatteries by using the current voltage and temperature of the batteriesfrom data received by the voltage and temperature sensors 63 andoptionally the historical data stored in the memory 67 of the controller60. The battery management controller then determines if the firstbattery has sufficient charge and if the second battery has sufficientcharge.

If neither battery has sufficient charge, the process proceeds to step408 in which the user is notified that there is insufficient batterycharge to run the accessory. The accessory is turned off, and theprocess ends at step 409.

If only the first battery has sufficient charge, the process proceeds tostep 410 in which the battery management controller 60 selects the firstbattery 40 as a power source and the accessory is operated at step 412.The current from the first battery 40 runs through the second battery 42as it travels from the first battery 40 through the third regulator 74to the load 78. As the accessory is running, the state of charge for thefirst battery is monitored by the controller 60 at step 414, and if thestate of charge of the first battery falls below a predetermined level,the first battery is deselected at step 416.

At step 418, the second battery is monitored to determine if it hassufficient state of charge to run the accessory. Although the secondbattery did not have sufficient charge in step 406, the charge of thesecond battery may have replenished after sitting around for a while. Inthe event that the second battery replenishes sufficiently to be used asa power source for the accessory, the second battery can be used topower the accessory.

At step 420, there is a comparison between the projected accessory runtime (based on state of charge of the second battery and/or user input)and the historical run time. For example, the power draw (current) fromthe HVAC system 10 is monitored and the rate of decline in the batteryis noted. The power draw and rate of decline is compared to historicaldata to determine the approximate state of sulfation of the batteryplates and from this comparison, the approximate condition of thebattery is deduced. Under a given load, the voltage of batteries in poorcondition will decline faster than batteries in good condition.Consequently, it may be predicted that batteries in poor condition willhave less total stored energy even though the actual voltage at anygiven time may be the same. In one example, data may be collectedrelated to the maximum battery discharge and/or the average batterydischarge during an operation cycle of the batteries. This data may becompiled over time such that a history of the maximum and/or averagebattery discharge is stored in the memory 67 in the battery managementcontroller 60.

As another example, user preferences which are inputted using the userinterface 51 are also factors that influence the extent to which thebatteries 40 and 42 will be allowed to be discharged. One example is thebattery replacement life. Battery replacement life is related to thedepth of the discharge of the power source as well as the rate ofdischarge, i.e., a function of the minimum battery voltage adjusted bythe load. For example, a lightly loaded battery which is consistentlydischarged to 11.8 V may only last through 100 charge/recharge cycleswhile a heavily loaded battery that was consistently discharged to 11.8V might last 200 charge/recharge cycles. If a user preference is set fora long battery life, the batteries will be less deeply discharged andwill last longer. However, because less stored energy will be availablefor use, more batteries will need to be carried to supply a given amountof cooling or heating than would be the case if a shorter battery life(and more deeply discharged batteries) were selected.

Based on the comparison of the projected accessory run time and thehistorical run time, the battery management controller 60 will send asignal to the HVAC component controller 50 so as to adjust the runningof these components so as to enable the operation of these componentsfor the full desired amount of time, as shown in step 422. As thevoltage of the second battery is being discharged, in step 424, thebattery management controller will continue to monitor the state ofcharge of the second battery, and send signals to the HVAC componentcontroller so as to adjust the running of the accessories based on thecurrent state of charge.

With continued operation of the HVAC system 10, the voltage of the firstbattery 40 continues to decline. The battery management controller logiccircuit re-analyzes the battery 40 by comparing real time data on thepower draw, the temperature and the rate of voltage decline with thestored historical data and the user input preferences to determine theamount of stored energy available.

A determination is made of the minimum system disconnect voltage, i.e.,the battery cut-out voltage. From this determination, a calculation ismade of the estimated time to battery depletion for the first batteryand this estimated time information is communicated to the HVACcomponent controller 50. Because the estimated time information is basedon both static data (such as historical and user input) and real-timedata (such as current voltage levels and temperatures), a change in theperformance, the system load or the ambient conditions during theoperation of the HVAC system 10 may change the estimated timeinformation which may increase or decrease the calculation of theavailable system run time. As long as there is sufficient voltage, thebattery management controller will continue to have the second batterypower the accessory and monitor the second battery's voltage level(and/or the current flow to and from the battery). However, the powermay eventually be depleted from the second battery 42 to the point wherethe voltage falls to the level calculated by the control logic circuitto be the minimum allowed, i.e., the battery cut-out voltage, anddisconnect the second battery 40. Once the state of charge of the secondbattery falls below the minimum allowed level, the process proceeds tosteps 408 and 409 in which the user is notified via the user interfaceof the insufficient battery charged to run the accessory and theaccessory is turned off.

Referring back to step 406, if only the second battery is determined tohave sufficient charge to run the accessory, the process proceeds tostep 426 in which the accessory starts running while only using thesecond battery as the power source. As the accessory is running, thestate of charge for the second battery is monitored by the controller 60at step 414. Step 416 does not really take place because the firstbattery was never selected as the power source for the accessory sothere is no need to deselect it. Thus, from step 414, the process maythen proceed to step 418. At step 418, the second battery is monitoredto determine if it has sufficient state of charge to run the accessory.

At step 420, there is a comparison between the projected accessory runtime (based on the state of charge of the second battery and/or userinput) and the historical run time, as previously described. Based onthe comparison of the projected accessory run time and the historicalrun time, the battery management controller 60 will send a signal to theHVAC component controller 50 so as to adjust the running of thesecomponents so as to enable the operation of these components for thefull desired amount of time, as shown in step 422. In step 424, thebattery management controller will continue to monitor the state ofcharge of the second battery, and send signals to the HVAC componentcontroller to adjust the running of the accessories based on the currentstate of charge. Once the state of charge of the second battery fallsbelow a predetermined level, the process proceeds to steps 408 and 409in which the user is notified via the user interface of the insufficientbattery charged to run the accessory and the accessory is turned off.

Referring back to step 406, if both the first and second batteries aredetermined to have sufficient charge to run the accessory, the processproceeds to step 428 in which the accessory started running while bothbatteries are used as the power source. As the accessory is running, thestate of charge for each battery is monitored by the controller 60 atstep 414. As the accessory is running, the state of charge for the firstbattery is monitored by the controller 60 at step 414, and if the stateof charge of the first battery falls below a predetermined level, thefirst battery is deselected at step 416. At step 418, the second batteryis monitored to determine if it has sufficient state of charge to runthe accessory.

At step 420, there is a comparison between the projected accessory runtime (based on state of charge of the second battery and/or user input)and the historical run time, as previously described. Based on thecomparison of the projected accessory run time and the historical runtime, the battery management controller 60 will send a signal to theHVAC component controller 50 so as to adjust the running of thesecomponents so as to enable the operation of these components for thefull desired amount of time, as shown in step 422. In step 424, thebattery management controller will continue to monitor the state ofcharge of the second battery, and send signals to the HVAC componentcontroller to adjust the running of the accessories based on the currentstate of charge. Once the state of charge of the second battery fallsbelow a predetermined level, the process proceeds to steps 408 and 409in which the user is notified via the user interface of the insufficientbattery charged to run the accessory and the accessory is turned off.

The process that the power system including the battery managementcontroller undergoes during an engine start mode is provided in FIG. 6(b). Initially, the engine is turned off as shown in step 450. Anoperator tries to start the engine at step 452. At the start up of theengine, a heavy electrical load is applied to the first battery 40causing the voltage of the first battery 40 to drop. The amount of dropdepends on the condition, the state of charge, and the temperature ofthe first battery 40 as well as the engine itself. Thus, there is achance that under certain adverse conditions, the voltage drop will beso severe as to prevent the engine from starting unless additionalelectrical power is made available. Alternatively or additionally, thedischarge of the first battery may be at such a level that there isinsufficient voltage for the engine starter. For example, the firstbattery may be already 80% discharged or even dead before applying theheavy electrical load. If the voltage or state of charge of the firstbattery is insufficient to start the engine, the battery managementcontroller provides a “start assist” function in which the secondbattery is used to charge the first battery up to a level sufficient tostart the engine.

At step 454, the battery management controller 60 monitors the voltageor state of charge of the first battery 40 (or the current flow to andfrom the battery) to determine if it falls below a preset limit, forexample, a voltage level that would prevent the first battery 40 fromstarting the engine. If the voltage of the first battery 40 does notfall below the preset limit, no further action is needed to be taken bythe battery management controller 60 in regard to starting the engine,as indicated in step 456, because there is sufficient voltage or chargein the battery to start the engine. Thus, the engine is started. If thevoltage of the first battery 40 falls below the preset limit, but theengine starts anyway, as indicated in step 458, no further action needsto be taken by the battery management controller 60 in regard tostarting the engine, as indicated in step 456. However, the batterymanagement controller may command that the first battery be recharged,as will be discussed later.

If the voltage of the first battery 40 falls below the preset limit, andthe engine fails to start, as indicated in step 460, the processproceeds to step 462 wherein the battery management controller 60notifies the user that the charging of the first battery is in process.The user may be notified through the display 51 and/or through any othersuitable audio, visual, or tactile indicator. At step 464, the batterymanagement controller 60 then controls the second regulator or converter73 to boost the voltage from the second battery 42 and use it to chargethe first battery 40 (the first battery charging mode). This boosting isaccomplished by the battery management controller adjusting a voltagedifference between the connecting first and second batteries to causecurrent to flow from the second battery to the first battery to therebycharge the first battery. In a simplified example, each battery isconnected to a DC-to-DC converter of the buck/boost type as aload/source. The determination of whether the first battery is a load(receiving current) or a source (sending current) depends upon the dutycycle of the switching transistor associated with it. Likewise, thedetermination of whether the second battery is a load (receivingcurrent) or a source (sending current) depends upon the duty cycle ofthe switching transistor associated with it. The duty cycles of theseswitching transistor is determined and controlled by the batterymanagement controller 60.

At step 468, the state of charge of the first battery 40 is monitoredand determined by the battery management controller 60. If the firstbattery 40 has sufficient charge, the process proceeds to step 470wherein the user is notified by the display 51 and/or any other suitableaudio, visual, or tactile indicator to retry starting the engine. Fromstep 470, the process proceeds back to step 452. If the first battery 40does not have sufficient charge, the recharging of the first battery 40with the voltage of the second battery 42 continues but the batterymanagement controller 60 also monitors the voltage of the second battery42 (or the current flow to and from the battery). If the second battery42 has sufficient charge, the recharging continues as indicated in step472 and the state of charge of the first battery 40 is monitored anddetermined by the battery management controller 60 as indicated in step468.

If at any point, during the recharging, the battery managementcontroller 60 determines that the second battery does not havesufficient charge to continue the recharging, the process proceeds tostep 470 wherein the user is notified by the display 51 and/or any othersuitable audio, visual, or tactile indicator to retry to start theengine. From step 470, the process proceeds back to step 452.Optionally, after a predetermined number of iterations, if the firstbattery does not gain sufficient charge to start the engine and thesecond battery does not have sufficient charge to recharge the firstbattery, the user can be notified by the display 51 and/or any othersuitable audio, visual, or tactile indicator to cease attempting tostart the engine.

To provide a more concrete example of the start assist function, if boththe first and second batteries, for example, are each discharged 80% andneither battery alone is suitable to start the engine. The batterymanagement system issues commands such that the last 20% charge left inthe second battery 42 is channeled through the second regulator 73 intothe first battery so as to charge up the first battery 40. Even thoughthe charge of the first battery 40 will become greater than the chargeof the second battery during the process of charging up the firstbattery, the charging up process will still continue until the firstbattery is charged up to a level so that the first battery can be usedto start the engine. For example, the first battery 40 will continue tobe charged if the first battery is charged to 25% while the secondbattery is depleted down to 15%. If the engine can start with a batterycharged to 30%, the charging process will continue to this point, eventhough the second battery may be depleted down to 10%. In this example,the second battery is used only to charge the first battery. Thischarging process may be more advantageous than merely directly couplingthe first and second batteries to each other and then directlyconnecting the coupled batteries to the starter. For instance, in anexample where the first battery is depleted and the second battery isfully charged, if both batteries are connected to each other, the secondbattery may be uncontrollably drained by the first battery instead ofbeing used to start the engine.

The process that the power system including the battery managementcontroller undergoes during a recharging mode is provided in FIG. 6( c).Upon the start up of the engine, a charge power source, such as anelectrical power generator 76 or alternator, is activated, as indicatedin step 900. The battery management controller 60 determines, in step902, the state of charge of the first and second batteries, and thenproceeds to step 904.

At step 904, there is a determination of whether there has been any userinput provided from the user interface 51. For example, the userinterface may be configured to allow a vehicle occupant to select theoperating mode of the second regulator or converter. For example, if theuser selected the first battery to be charged first, the processproceeds to step 905 in which the battery management controller controlsthe first regulator 72 to regulate the amount of current flowing fromthe generator so that it charges the first battery before the secondbattery. Similarly, if the user selected the second battery to becharged first, the process proceeds to step 905 in which the batterymanagement controller controls the first regulator 72 to regulate theamount of current flowing from the generator so that it charges thesecond battery before the first battery. However, as the selectedbattery charges up, a situation may occur in which the voltage of theselected battery being charged up by the power generator exceeds thevoltage of the unselected battery. In such an instance, to prevent thecurrent from flowing through the selected battery and into theunselected battery, the battery management controller 60 may control thesecond regulator 73 so that it is in a neutral mode to prevent anycurrent from flowing between the two batteries or in a mode to ensurethat only the selected battery is being charged.

Once the selected battery reaches a predetermined threshold such that itcan be considered suitably charged, the process can proceed to step 906in which the remaining battery is recharged. In this instance, the firstregulator 72 may be controlled by the battery management controller 60to only charge up the remaining controller. Alternatively, the firstregulator 72 may be controlled to charge up both batteries but thesecond regulator 73 may be controlled such that the current will flowthrough the suitably charged battery and into the remaining battery,which may result in the suitably charged battery being “topped off.”

As an alternative to steps 905 and 906, the user may select that boththe batteries be charged at the same time. In this instance, the usermay selected the charging rates upon which each battery should becharged. For example, if the user wishes to have both batteries chargedat the same rate, the first and second regulators 72 and 73 may becontrolled by the battery management controller 60 such that the sameamount of current will flow into each battery, regardless of theirrespective states of charge. In addition, if the user wishes to have thebatteries both be charged at different charging rates, the first andsecond regulators 72 and 73 may be controlled such that these rates canbe accomplished by controlling the amount of current flow to eachbattery from the power generator and the amount of current flow from onebattery to another. Thus, the battery management controller can controlthe first and/or second regulators to increase the amount of currentflowing from the generator to one of the first and second batteries.Whether charged sequentially or concurrently, the power generatorcontinues to recharge the batteries until they are both above a suitablerespective threshold at which the recharging may cease or until theengine is stopped.

Referring back to step 904, if there is no user input, the batterymanagement controller may determine the charging rates of the first andsecond batteries based on a level of charge. In one example, one battery(such as the first battery used as a starter battery) may be selected tobe charged first over the other if it falls below a certain threshold(step 908), and then the remaining battery is charged after the selectedbattery is suitably charged (step 910). Alternatively, both batteriesmay be charged at different charging rates based on the level of chargeof each battery or other similar criteria. Whether charged sequentiallyor concurrently, the power generator continues to recharge the batteriesuntil they are both above a suitable respective threshold at which therecharging may cease or until the engine is stopped.

FIG. 7 shows another embodiment of the power system 70′. Theconfiguration of the power system 70′ is the same as the configurationof FIG. 5 with the following exceptions. First, the first battery 40′ isnot a starter battery but merely an auxiliary bank of batteries whilethe second battery 42′ is the main bank of batteries. In addition, thethird regulator has been removed and the power from the second batteryis directly channeled into the load 78, such as the variable-speed HVACsystem.

FIG. 8 shows another embodiment of the power system 70″. Theconfiguration of the power system 70″ is the same as the configurationof FIG. 5 with the following exceptions. First, the first battery 40′ isnot a starter battery but merely an auxiliary bank of batteries whilethe second battery 42′ is the main bank of batteries. In addition, thethird regulator has been removed and the power from the first and secondbatteries is fed into the load 78 via the second regulator 73′. Thesecond regulator 73′ acts as a buck/boost DC-to-DC converter and as theboost regulator to the load 78. The second regulator then permitscurrent to flow between the first and second batteries as described inrelation to the second regulator 73 in FIG. 5, but also current can flowfrom the first and/or second battery to the load 78 based on the dutycycle of the switching transistor associated with the respective firstbattery, second battery, and load 78.

FIG. 9 shows another embodiment of the power system 70′″. Theconfiguration of the power system 70′″ is the same as the configurationof FIG. 8 with the following exception. Instead of an electrical powergenerator 76 comprising a single alternator, the power generatorcomprises two charging devices 82 and 84. Each charging device may be,for example, a wind turbine generator, a hydro turbine generator, adiesel generator, a gas turbine generator, an alternator, an AC source,one or more solar panels or any other power source. Both chargingdevices are connected to the first regulator 73.

FIG. 10 shows another embodiment of the power system 70″″. Theconfiguration of the power system 70″″ is the same as the configurationof FIG. 8 with the following exceptions. First, instead of an electricalpower generator 76 comprising a single alternator, the power generatorcomprises a motor/generator 86. Second, the first regulator 72′ acts asa buck/boost DC-to-DC converter from the first and second batteries tothe motor generator 86. The first regulator then permits current to flowfrom the generator to the first and second batteries as described inrelation to the first regulator 72 in FIG. 5, but also current can flowfrom either or both the first and second batteries to the motor 86 basedon the duty cycle of the switching transistor associated with therespective first battery, second battery, and motor/generator 86. Thebattery management controller 60 may determine what mode themotor/generator is in, and whether power from the first and/or secondbatteries are required to power the motor/generator when in the motormode.

In yet another embodiment of the power system, the configuration of thepower system may be the same as the configuration of FIG. 5 with thefollowing exception. One of the batteries is only charged by the otherbattery. For example, the first battery may be charged only by thesecond battery or the second battery may be only charged by the firstbattery. The configuration can be accomplished by removing theelectrical connection from the first regulator to either one of thefirst and second battery. Alternatively, only one of the batteries isattached to the electric power generator 76 without even including thefirst regulator 72. In yet another alternative, the configuration may bethe same as FIG. 5 but that the first and second regulators 72 and 73are always controlled by the battery management controller 60 so thatone of the batteries is only charged by the other battery.

Because the first and second power source may be batteries, they maybenefit from a periodic controlled overcharge, which is often referredto as an equalization charge. The equalization charge mixes up theelectrolyte, which tends to stratify or separate into overlapping layersof acid and water and also helps remove some sulfate deposits. During anequalization charge, the battery is charged well after the point atwhich the battery would be normally considered to be fully-charged whileavoiding excessive battery heating or electrolyte boil-off. For example,a battery voltage is allowed to rise to a high voltage (such asapproximately 16, 17, or more volts for a 12 volt battery), where it ismaintained for a length of time (for example, up to 7, 8, 9 or morehours) by adjusting of the charging current. Of course, it should bekept mind that if the first or second battery is a battery bank, theequalization charge would apply across the battery bank.

According to one embodiment of the present invention, the powergenerator 76 (such as an alternator) may be used to provide an elevatedvoltage for the equalization charge for one of the first (secondary)battery and the second (main) battery. For example, based on user inputfrom the user interface 51, the battery management controller 60 may beconfigured to control the power system 70 to conduct an equalizationcharge of one of the first (secondary) battery and the second (main)battery using the electrical generator to raise an output voltage to anincreased value greater than the normal output voltage in order toconduct an equalization charge of one of the first (secondary) batteryor the second (main) battery. To achieve this rise in output voltage,the battery management controller 60 may adjust the excitation of theelectrical generator.

According to another embodiment of the present invention, one batterymay be used to elevate the charge of the other battery so that the otherbattery undergoes an equalization charge. For example, based on userinput from the user interface 51, the battery management controller 60may be configured to control the power system 70 to conduct anequalization charge of one of the first (secondary) battery and thesecond (main) battery using the other of the first (secondary) batteryor the second (main) battery) by controlling the second regulator 72such that a voltage difference is sufficiently created between the firstand second batteries to cause a flow of current from one battery to theother such that the other battery undergoes an equalization charge.

Next, the HVAC component controller 50 will be described. The HVACcomponent controller 50 controls the components of the HVAC system 10,and works in conjunction with the battery management controller 60. Thepurpose of the HVAC component controller 50 is to: (1) communicate tothe user via the user interface; (2) monitor safety functions andinitiate appropriate responses; (3) maximize the operational efficiencyof the HVAC system by optimizing the speed of the condenser andevaporator fans and the speed of the compressor motor according toambient conditions and user preferences; (4) regulate the speed of thecondenser fans to control the condenser temperature thereby obtainingthe best compromise between increased fan motor power consumption andincreased compressor motor power; (5) regulate the speed of theevaporator fan proportionate to the temperature differential between theuser temperature set point and the actual ambient temperature; and (6)regulate the speed of the compressor motor to maintain the desiredevaporator temperature.

The HVAC component controller 50 carries out its function by beingoperationally connected to the battery management controller 60, theuser interface 51 (which includes a display 310 and one or more inputs312), a plurality of sensors, and the operational components of the HVACsystem as show in FIG. 11. The plurality of sensor detects a variety ofparameters including: the vehicle's interior ambient temperaturedetected by a temperature sensor 304, the humidity of the vehicle'scompartments by using a humidity sensor 307, and noise and/or vibrationfrom one or more noise or vibration sensors 308.

As to the operational components of the HVAC system, the HVAC componentcontroller 50 may run the motor 12 that drives the compressor 14; thecirculation blowers that blow the temperature-controlled air into one ormore designated compartments (such as the vehicle compartment 23 and/orthe sleeping compartment 27); the heaters for the heating system (suchas the air heaters 272 and 274 from FIG. 1 or the heater 180 from FIG.2); and the control doors (if applicable) for the regulation of thetemperature. Additionally the HVAC component controller 50 may alsoswitch any control valves to control the flow of refrigerants (such asthe valves 28 and 29 from FIG. 1 or the valves 184 and 184 from FIG. 2).In one embodiment, the motor 12 of the compressor 14 may be controlledby the HVAC component controller 50 using a closed loop proportional,integral, derivative (PID) control. Similarly, the HVAC componentcontroller 50 may also control the fan speed of the circulation blowers210 and 212 via a pulse width modulated (PWM) PID control loop that isindependent of the control for the compressor.

In one embodiment, the HVAC component controller 50 may modulate thespeed of the motor 12, and thus may modulate the capacity of thecompressor 14 driven by the motor 12. The modulation of the compressormay range between an upper compressor capacity and a lower compressorcapacity. The compressor capacity may vary depending on the compressorcapacity required to maintain the evaporator 22 or 26 at the evaporatortemperature T_(E) as commanded by the control logic circuit 66.

In one exemplary embodiment of the present invention, the HVAC componentcontroller 50 (“HCC”) may work as described below with reference to FIG.12. The HVAC component controller 50 receives a signal from the userinterface 51 to begin operation at step 702. Commands are sent to thebattery management controller 60 (“BMC”) from the HVAC componentcontroller 50 to supply power to the HVAC system 10 at step 704. Theuser interface 51 is polled for the user preference settings, such asthe mode of operation, the location of temperature control, and thedesired set point temperature T_(sp). Also the ambient temperature T_(a)is read from the temperature sensor 304 at step 706.

If the user preference is for the “cooling” mode, the process is sent tostep 708 where a command is issued to start all fans of the circulationblowers 210, 212 and the motor 12 of the compressor 14 to a minimumspeed. At step 710, the compressor speed is then commanded to bring andhold the evaporator 22 to a predetermined evaporator temperature T_(E)if the vehicle compartment is being cooled or to bring and hold theevaporator 26 to a predetermined evaporator temperature T_(E) if thesleeping compartment is being cooled. At step 712, the fans of thecondenser 16 are commanded to bring and hold the condenser 16 to apredetermined condenser temperature T_(C).

If the user preference is for the “heating” mode, a command from theHVAC component controller 50 is issued at step 714 to start the fans ofthe circulation blowers of the evaporator 22 or 26. The electric heatingelement 270 or 274 is commanded at step 716 to a power level (via PWMcontrol) proportionate to the fan speed of the circulation blowers ofthe evaporator 22 or 26.

With the HVAC system 10 now running in either the heating or coolingmode, the battery management controller 60 is polled for an estimate ofthe run time based on the present power draw and stored energy availablefor use in step 718. As step 720, the estimated run time is compared tothe desired run time which was programmed into the user settings by theuser using the user interface 51. The HVAC component controller factorsthe difference between the estimated and desired run times into planningthe output of the HVAC system 10 to ensure that sufficient power isavailable for the duration of the heating or cooling period (also calledthe “run time plan”). Based on the run time plan, the HVAC componentcontroller 50 may increase or decrease the average capacity of the HVACsystem periodically throughout the cycle. In particular, if the amountof heating (steps 726 and 736) or the amount of cooling (steps 726, 728,and 730) would require too much power to be drawn from the powersource(s), the highest capacity of the HVAC system 10 possible would beemployed which would still allow the battery management controller tosupply power through the entire operational period. The highest capacitypossible may be obtained through a combination of settings which wouldoffer the best efficiency for the prevailing conditions.

At step 722, a variety of measurements are taken at step 722 so as toensure that the HVAC system runs efficiently with its limited powersupply. These measurements include the actual ambient temperature of thevehicle's interior T_(a), the evaporator temperature T_(E), and thecondenser temperature T_(C). At step 722, temperature sensors on theevaporator measure the evaporator temperature T_(E), temperature sensorson the condenser measure the condenser temperature T_(C), sensors in thevehicle and/or sleeping compartments measure the ambient temperatureT_(a), and the user inputs the desired ambient temperature or the setpoint temperature T_(sp) via the user interface 51.

For efficient operation of the HVAC components in either the cooling orheating mode, a calculation is made at step 724 in which a difference Δbetween the ambient temperature T_(a) and the set point temperatureT_(sp) is determined. Then, the circulation blowers at the evaporator 22or 26 are commanded to a speed proportionate to the difference Δ at step726. The determination of an appropriate fan speed for the blowers atthe evaporator based on a given Δ may be based on any one of a number ofmethods known in the art such as tabular formulations or computermodels.

The air blown into the vehicle and/or sleeping compartments affects theambient temperature of the compartment; thus with continued operation ofthe HVAC system, the difference (Δ) between the ambient temperatureT_(a) and the set point temperature T_(sp) begins to decrease. As theambient temperature T_(a) nears the set point temperature T_(sp) theHVAC component controller 50 reduces the fan speed of the circulationblowers at the evaporator 22 or 26 proportionately based on Δ, as seenin step 726. If the system is in the cooling mode, the reduced air flowover the evaporator 22 or 26 causes the evaporator temperature T_(E) tofall. In response, the HVAC component controller 50 adjusts the speed ofthe motor 12 that drives the compressor 14 to maintain the desiredevaporator temperature T_(E) at step 728. Similarly, the changingcapacity of the evaporator 22 or 26 also changes the temperature of thecondenser T_(C). Again, the HVAC component controller 50 adjusts the fanspeed of the condenser 16 so as to maintain the desired condensingtemperature T_(C) at step 730. However, the settings for the circulationblowers, the compressor, and the condenser (which are set in steps 726,728, and 730 respectively) are subject to the highest possible capacityof the HVAC system based on the run time plan. Thus, if too much powerwould be drawn by these components while running at the most efficientoperation, the settings of these components would be adjusted so as toallow the system to run for the desired run time while operating asclose as possible to the most efficient operation determined by Δ.

The process continues to step 732 where the HVAC component controllerreceives data from the battery management controller 60 about whetherthere is sufficient power being supplied. If there is sufficient power(the “YES” path), the process returns to step 718 and the process isrepeated. If there is insufficient power (the “NO” path), the operationof the HVAC system is terminated at step 734.

If the HVAC system is operating in heating mode rather than the coolingmode, the HVAC component controller 50 alters the PWM cycle of theresistive heating elements 270 or 274 to match the changing fan speed ofthe circulation blower at the evaporator 22 or 26. In this way, thetemperature of the discharged air remains constant. Thus, step 736 iscarried out in FIG. 12 instead of steps 728 and 730. Similar with thecooling operation, the settings for the circulation blowers and theheater (which are set in steps 726 and 736 respectively) are subject tothe highest possible capacity of the HVAC system based on the run timeplan. Thus, if too much power is being drawn by these components whilerunning at the most efficient operation, the settings of thesecomponents may be adjusted so as to allow the system to run for thedesired run time while operating as close as possible to the mostefficient operation determined by Δ. For example, the settings of thecirculation blowers may be lowered to a level that permits operationduring the entire desired run time while still operating as close aspossible to the settings for the most efficient operation based on A.

Other system parameters may be used to control the motor-drivencompressor 14 and the circulation blowers 210 and 212. For example, theHVAC component controller 50 may also monitor humidity of the vehicle'scompartments by using a humidity sensor 307. If the humidity of thecompartments is above a predetermined threshold (which may be set by thevehicle occupant), the HVAC component controller 50 may control thecompressor 14 to speed up (up to but not exceeding the upper compressorcapacity) and the circulation blowers 210 and 210 to slow down.

Furthermore, one or more noise or vibration sensors 308 may be used todetermine the level of noise or vibration of the HVAC system 10. Oncethe signal is sent to the HVAC component controller 50, the controller50 determines whether there is a need to speed up or slow down thecompressor and/or blower, and to control the compressor and/or bloweraccordingly.

The use of one or more system parameters, such as the evaporatortemperature, the humidity, the exterior ambient temperature, thevehicle's interior temperature, etc. to control the compressor andblower capacities may be accomplished by monitoring the one or moresystem parameters and using a program in the HVAC component controller50 that was compiled using, for example, a multivariate model known inthe art.

Other system parameters may also be provided to the HVAC componentcontroller 5, which may allow the HVAC component controller 50 to detectfaults within the HVAC system. For example, performance and safetyfunctions are monitored and an appropriate response by the HVACcomponent controller 50 may be initiated, such as shutting down thesystem in the event of the overheating of the motor 12 of the compressor14.

FIG. 13 shows another embodiment of the HVAC system according to thepresent invention. The embodiment in FIG. 13 is similar to theembodiment of FIG. 1; however, FIG. 13 shows how the HVAC system may bedivided up into a split system 600 in which there is an exteriorsubsystem 602 and an interior subsystem 604. The exterior subsystem 602may comprise components that are located on the exterior area of thevehicle's cab. The interior subsystem 604 may comprise components thatare located in the interior area of the vehicle's cab, wherein theinterior area includes a driver compartment and a sleeper compartment.The driver compartment is at least partially segregated from the sleepercompartment. FIG. 13 shows an exterior subsystem 602 that comprises amotor 12, a compressor 14, a condenser 16, and a first power source,which are located outside the cab of a large vehicle, such as a truck.In addition, the second power source and the electrical power generationsystem 44 may also be located on the exterior of the vehicle's cab as isconventional with large vehicles. The exterior subsystem is mounted to alocation outside the interior area. For example, the exterior subsystemis mounted to a rear side of the interior area or is mounted underneaththe interior area.

The interior subsystem is mounted within the interior area and is to beoperably connected with the exterior subsystem. The interior subsystemmay mounted in the sleeper compartment, such as underneath a bed in thesleeper compartment. The interior subsystem 604 may comprise thecirculation blower 610, the evaporator 622 and the HVAC componentcontroller 50, the battery management controller 60, the display 310,and the input device 312, which are all located inside the cab of thevehicle. The temperature controlled air may be optionally channeled intoducts 672, which may split into two or more ducts that may lead todifferent compartments or areas of the interior of the vehicle's cab. Inone embodiment, the ducts 672 may be the vehicle's own ducting which isalready installed in the vehicle cab. Additionally, the interiorsubsystem 604 may comprise the vehicle's already existing evaporator 622and circulation blower 610. In such a situation, the exterior subsystem602 may be configured to be able to connect to a plurality of differentevaporators, such as the vehicle's own evaporator. In addition, theexterior subsystem 602 may be configured to connect to a plurality ofevaporators at one time, such as one evaporator for cooling/heating thedriving compartment and one evaporator for cooling/heating the sleepingcompartment.

In FIG. 13, the refrigerant metering device is located exterior to thevehicle's cab as part of the exterior subsystem 602, which allows theservicing of the metering device to be easier if it should fail.Alternatively, the refrigerant metering device 20 may be located in theinterior of the cab as part of the interior subsystem 604.

The interior and exterior subsystems may be connected to each other by aliquid phase cooler 1002, as shown in FIG. 15. The liquid phase cooler1002 comprises an outer tube 1004 with two first connectors 1010 and aninner tube 1008 with two second connectors 1006. The inner tube 1008 isplaced within the outer tube 1004. The tube may be made of any suitablematerial, such as plastic. Liquid refrigerant can be transferred withinthe inner tube 1008 or in the outer tube 1004 while gas refrigerant canbe transferred in the other tube. The ends 1012 of the outer tube 1004are sealed so that the fluid running between the inner wall of the outertube and the outer wall of the inner tube does not leak. If liquidrefrigerant is transferred between the inner wall of the outer tube andthe outer wall of the inner tube, there is an additional benefit thatinsulation would not be needed. Furthermore, the boiling of liquidcaused by the heating of the liquid by the sun is inhibited; therebyimproving the efficiency of the cooling. Also, having one tube insideanother would effectively be similar to having a single tube, whichwould be easier to attach to the back of a truck.

According to one embodiment, the exterior subsystem 602 further includesa quick connect inlet port 1014 and a quick connect outlet port 1016.The interior subsystem 604 further includes a quick connect inlet port1018 and a quick connect outlet port 1020. The inner and outer tubes1004 and 1008 are first and second quick connect lines, respectively,for operably connecting the exterior subsystem 602 and the interiorsubsystem 604. The first quick connect line 1008 connects the quickconnect inlet port 1014 of the exterior subsystem 602 and the quickconnect outlet port 1020 of the interior subsystem 604. The second quickconnect line 1004 connects the quick connect inlet port 1018 of theinterior subsystem 604 and the quick connect outlet port 1016 of theexterior subsystem 602.

The quick connect inlet port 1014 and the quick connect outlet port 1016of the exterior subsystem 602 and the quick connect inlet port 1018 andthe quick connect outlet port 1020 of the interior subsystem 604 may below loss quick connect ports. The first and second quick connect lines1004 and 1008 may be low loss quick connect lines with low loss quickconnectors 1006 and 1010, as seen in FIG. 16( a). For low loss quicklines, fluid is retained in the lines because of spring-loaded seals1024 located in the connectors 1006 and 1010. When the connectors 1006and 1010 are attached to their respective mating ports 1014, 1016, 1018,and 1020, a plunger 1022 within the respective port depresses the springloaded-seal 1024, thus permitting fluid to flow through the connectlines. When the connectors and ports are disconnected, the plunger 1022removes its pressing force from the spring-loaded seal 1024, thuspermitting the seal 1024 to spring back into its sealing position, whichallows the fluid within the connect lines to be retained. Therefore, thelow loss quick connect ports and the low loss quick connect lines 1004and 1008 removably connect so that connection and disconnection can takeplace multiple times with low loss of refrigerant fluid.

Alternatively, the quick connect inlet port 1014 and the quick connectoutlet port 1016 of the exterior subsystem 602 and the quick connectinlet port 1018 and the quick connect outlet port 1020 of the interiorsubsystem 604 may be one-time quick connect ports. The first and secondquick connect lines 1004 and 1008 may be one-time quick connect lineswith one-time quick connectors 1006 and 1010, as seen in FIG. 16( b).For one-time quick lines, fluid is retained in the lines because ofmembranes 1028 located in the connectors 1006 and 1010 providing a seal.When the connectors 1006 and 1010 are attached to their respectivemating ports 1014, 1016, 1018, and 1020, a knife-edge 1026 punctures orruptures the membrane 1028 within the respective port; thus permittingfluid to flow through the connect lines. The one-time quick connectports and the low loss quick connect lines 1004 and 1008 will leak ifthe connectors are removed from their respective ports but provides theadvantage of being smaller than the low-loss connectors.

Of course, other connectors and lines may be used for the connectors1006 and 1010 and the connect lines 1004 and 1008. For example, theconnectors 1006 and 1010 may have flared fittings, sealed fittings, etc.Additionally, various combinations of fitting may be used. For example,both connectors 1010 and 1006 may be low-loss quick connectors, one-timequick connectors, or a combination thereof. According to one embodiment,one of the connectors 1010 and the connectors 1006 are low-lossconnectors while the other of the connectors 1010 and the connectors1006 are one-time quick connectors. According to another embodiment, theconnectors 1006 and 1010 that lead to the evaporator 622 (i.e.,connecting to the inlet port 1018 and the outlet port 1020 of theinterior subsystem 604) may be one-time quick connectors while theconnectors 1006 and 1010 that lead to the condenser 16 (i.e., connectingto the inlet port 1014 and the outlet port 1016 of the exteriorsubsystem 602) may be any suitable connector, such as one-time quickconnectors, low-loss quick connectors, flared connectors, etc.

The split system 600 has several advantages. First, less interior spaceis taken up by the system because a substantial portion of thecomponents are located exterior to the vehicle's cab. Additionally, thevehicle's existing ducts may be used so that no additional ducting isneeded. Thus, the system may have an easier installation process,improved efficiency, and quieter operation.

The disclosed battery management controller and HVAC system may providetemperature control to a vehicle occupant for extended periods of timewhen the vehicle's engine is not running. In addition, the systemensures sufficient battery power to start the vehicle even when the HVACsystem has been running for a period of time when the engine has beenturned off. The battery management and HVAC systems may be used in largetrucks, such as 18 wheelers, as well as any other type of vehicle.

During operation, the HVAC component controller 30 processes the userinputs to determine the operational mode of the HVAC system 10. Wheneither the heating or cooling mode of operation is selected and when theengine is turned on, the vehicle electrical power generation system isused to power the necessary components. For example, the heater andcirculation blowers are turned on during the heating mode of operationwhile the compressor, circulation blowers, and pumps are turned onduring the cooling mode of operation.

When the heating mode is operating when the engine is turned off, theHVAC component controller 50 commands a heater (such as the coolantheater 180 in FIG. 2 or the air heaters 270 and 274 in FIG. 1) and thecirculation blowers 210 and 212 to turn on. The HVAC componentcontroller 50 also controls the speed of the circulation blowers 210 and212 via a pulse width modulated (PWM) PID control loop in order tomaintain the temperature of the driving and/or sleeping compartment atthe interior set point temperature. With the various disclosedembodiments, the heating of the interior of the cab may be performedwithout relying on diesel fuel but may be run purely by battery power.Thus, the heating may be performed without relying on the vehicle'sengine being turned on.

When the cooling mode of operation is used when the engine is turnedoff, the circulation blowers 210 and 212, the compressor 14 and/or thepump 176 are turned on. The HVAC component controller 50 modulates thecapacity of the compressor 14 and the circulation blowers 210 and 212 tomaintain the temperature of the driving and/or sleeping compartment atthe interior set point temperature via PID control.

In either the heating or cooling mode when the engine is turned off, ifthe voltage of the combination of the first and second power sourcesdrops below a predetermined amount, the first and/or second power sourceis disconnected and the HVAC system is only powered by the remainingpower source. Once the voltage of the remaining power source drops belowanother predetermined level, the battery management controller 60 may beconfigured to disconnect the remaining power source, thus shutting downthe HVAC system 10.

Upon start up of the vehicle, the alternator or other charging devicemay be used to charge up the first and second power sources (if they arebatteries) so that they are fully charged. In one embodiment of thepresent invention, the battery management controller 60 may also be usedto connect the first power source (such as an auxiliary battery or bankof auxiliary batteries) during the start up of the vehicle in thesituation where the second power source (such as the starter battery orbank of batteries) is too weak to start the vehicle, such as in the casewhere the starter battery is weakened because of very low exteriorambient temperatures.

Furthermore, the HVAC system may be a split system with a substantialportion of the components exterior to the vehicle's cab such that lessinterior space is taken up by the HVAC system. Also, the vehicle'sexisting evaporator and/or ducting may be used with the HVAC system foran easier installation process, improved efficiency, and quieteroperation.

Operation of the battery management controller will now be described ingeneral with regard to FIG. 14, which discloses a power generationsystem. FIG. 14 discloses a power generation system including a pair ofpower generators 101, 102. The generation system also includes main andauxiliary battery systems 131, 132. The power generators are connectedto an AC power distribution bus 150 and the battery systems areconnected to a DC power distribution bus 145. Although AC and DC bussesare shown, the power generation system may include a single DC bus. Thepower generation system includes AC load(s) 105 and DC load(s) 110. Asmentioned above, the loads may be supplied by a single DC distributionbus and individual inverters provided for each AC load. As shown in FIG.14, the power generation system may include an inverter 103 forconverting AC to DC power. Alternatively, the system may include amotor/generator set for handling DC/AC or AC/DC power conversion.

As shown in FIG. 14, the system includes AC power generators but,alternatively, a primary source of DC power may be provided. The powergenerators 101, 102 may serve as a charge source for the battery systems131, 132. For example, the power generators may include, for example, awind turbine generator, a hydro turbine generator, a diesel generator,and a gas turbine generator, etc. The power generation system mayinclude several power transfer units (PTUs) 120 controlled by a batterymanagement or system controller 175. The PTUs may simply be switchescontrolling the flow of power along their respective lines The PTUs maybe mounted on one or more printed circuit boards and connected to thenecessary wiring, electrical connections, and/or bus bars by anysuitable means, such as wave soldering. The system may also include apower booster unit 127 (as described above).

The battery management controller 175 may include a control logiccircuit and a memory, and may be connected to various system sensors.The battery management controller may be used to regulate the degree ofdischarge among the power sources so as to conform to the userpreferences for battery change and use of various power sources. Thememory 67 of the battery management controller may be used to loghistorical data and use the historical data to modify the operation ofthe system.

In one exemplary embodiment, the power generator 102 corresponds to awind turbine generator used for battery charging. The controller 175 isconfigured to control the system so that the battery could eitherreceive power from the generator 102 or provide power (i.e., motorize)the wind turbine. For example, during periods of no or little wind, thebattery (or batteries) could be employed to power the generator 102 todrive the turbine blades and keep the blades spinning at a reasonablerate of speed. Maintaining the turbine rotating, would improve theefficiency of the wind turbine because when the turbine is always readyto make efficient use of each gust of wind to once again charge thebatteries. There would be no losses associated with starting or speedingup the turbine.

The system FIG. 14 is an exemplary power generation system that mayoperate on similar principles to those described above with regard toFIGS. 1-8. However, FIG. 14 demonstrates that the concepts herein havebroad applicability to various power generation systems includingmultiple power sources including stored energy and rechargeable powersources.

Given the disclosure of the present invention, one versed in the artwould appreciate that there may be other embodiments and modificationswithin the scope and spirit of the invention. Accordingly, allmodifications attainable by one versed in the art from the presentdisclosure within the scope and spirit of the present invention are tobe included as further embodiments of the present invention. The scopeof the present invention is to be defined as set forth in the followingclaims.

1. A power system to be installed in a vehicle comprising: a firstbattery having a first battery voltage and a second battery having asecond battery voltage; an electrical power generator configured tocharge the first battery; an electrical load powered by at least one ofthe first battery, the second battery or the electrical power generator;a converter connected to both the first and second batteries andconfigured to operate in either a neutral mode or a first batterycharging mode or a second battery charging mode, wherein the converteris configured to create a voltage difference between the first andsecond batteries in the charging modes; and a battery managementcontroller configured to monitor the first voltage of the first batteryand the second voltage of the second battery and/or to monitor currentflow to and from the first and second batteries, and wherein thecontroller controls operation of the converter to operate in either theneutral mode, the first battery charging mode or the second batterycharging mode; wherein in the second battery charging mode, theconverter is configured to adjust the voltage difference between firstbattery and the second battery to cause current to flow from the firstbattery to the second battery to thereby charge the second battery. 2.The system of claim 1, wherein the second battery is only charged by thefirst battery.
 3. The system of claim 1, further comprising a userinterface configured to allow a vehicle occupant to select the operatingmode of the converter.
 4. The system of claim 1, wherein the generatorcomprises an alternator configured to be driven by an engine of thevehicle.
 5. The system of claim 4, wherein the controller is configuredto control excitation of the alternator in order to control alternatoroutput voltage.
 6. The system of claim 1, wherein in the first batterycharging mode, the converter is configured to adjust the voltagedifference between the first battery and the second battery to causecurrent to flow from the second battery to the first battery to therebycharge the first battery.
 7. The system of claim 1, wherein in theneutral mode the converter is configured so that no current flowsbetween the first and second batteries.
 8. The system of claim 1,wherein the electrical load comprises a system for heating a compartmentof the vehicle.
 9. The system of claim 1, wherein the electrical loadcomprises a system for cooling a compartment of the vehicle.
 10. Thesystem of claim 1, further comprising a current regulator connected tothe generator and at least one of the first and second batteries,wherein the controller controls the current regulator to regulate theamount of current flowing from the generator to the at least one of thefirst and second batteries.
 11. The system of claim 10, wherein thecontroller is configured to control the current regulator and theconverter to adjust relative charging rates of the first and secondbatteries.
 12. The system of claim 1, further comprising a boostconverter connected to at least one of the first and second batteriesand the load, wherein the boost converter raises the voltage beingsupplied to the load by the at least one of the first and secondbatteries.
 13. The system of claim 12, wherein the controller controlsthe boost converter to adjust the power being supplied to the load fromthe at least one of the first and second batteries.
 14. The system ofclaim 1, wherein one of the first and second batteries is connected to avehicle starting system to provide power to start an engine of thevehicle.
 15. A vehicle power system comprising: an electrical generatordriven by an engine of a vehicle, a main battery connected to asecondary battery for supplying current an electrical load; and acontroller coupled to the main battery and the secondary battery; andwherein the controller is configured to adjust the system so that themain battery is charged by the secondary battery when a state of chargeof the main battery is below a predetermined threshold even when a stateof charge of the secondary battery is less than the state of charge ofthe main battery.
 16. The system of claim 15, further comprising aconverter connected between the main and secondary batteries to controlcurrent flow between the main battery and the secondary battery.
 17. Thesystem of claim 16, wherein the controller is configured to control thesystem to conduct an equalization charge of one of the main battery andsecondary battery using the other of the main battery and the secondarybattery.
 18. The system of claim 15, wherein the controller isconfigured to control the generator to raise an output voltage to anincreased value greater than a normal output voltage in order to conductan equalization charge of one of the main battery and the secondarybattery.
 19. The system of claim 18, wherein the controller adjustsexcitation of the generator in order to raise the output voltage. 20.The system of claim 18, further comprising a current regulator connectedto the generator and at least one of the main battery and the secondarybattery, wherein the controller controls the current regulator toincrease the amount of current flowing from the generator to the one ofthe main and secondary batteries being charged.
 21. The system of claim15, wherein the main battery is used as a starter battery, and thedetermined threshold is a level of charge sufficient to start the engineof the vehicle.
 22. The system of claim 21, wherein the controller isconfigured to adjust the system so that the secondary battery chargesthe main battery to the predetermined level sufficient to start theengine of the vehicle even if the state of charge of the secondarybattery is less than the state of charge of the main battery.
 23. Avehicle comprising: an interior area including a driver compartment anda sleeper compartment; an interior subsystem comprising a blower and anevaporator; and an exterior subsystem comprising a compressor and acondenser, wherein the exterior subsystem is mounted to a locationoutside the interior area, wherein the interior subsystem is mountedwithin the interior area and to be operably connected with the exteriorsubsystem.
 24. The vehicle of claim 23, wherein the exterior subsystemis mounted to a rear side of the interior area.
 25. The vehicle of claim23, wherein the interior subsystem is mounted in the sleepercompartment.
 26. The vehicle of claim 25, wherein the interior subsystemis mounted underneath a bed in the sleeper compartment.
 27. The vehicleof claim 23, wherein the exterior subsystem is mounted underneath theinterior area.
 28. The vehicle of claim 23, a liquid phase coolercomprising an outer tube with two first connectors and an inner tubewith two second connectors, wherein the inner tube is placed within theouter tube.
 29. The vehicle of claim 28, wherein the exterior subsystemfurther includes a quick connect inlet port and a quick connect outletport, wherein the interior subsystem further includes a quick connectinlet port and a quick connect outlet port; wherein the inner and outertubes are first and second quick connect lines, respectively, foroperably connecting the exterior subsystem and the interior subsystem,wherein the first quick connect line connects the quick connect inletport of the exterior subsystem and the quick connect outlet port of theinterior subsystem, and wherein the second quick connect line connectsthe quick connect inlet port of the interior subsystem and the quickconnect outlet port of the exterior subsystem.
 30. The vehicle of claim29, wherein the quick connect inlet port and the quick connect outletport of the exterior subsystem and the quick connect inlet port and thequick connect outlet port of the interior subsystem are one-time quickconnect ports, wherein each first and second quick connect linecomprises end connectors at both ends, and wherein the first and secondquick connect lines are one-time quick connect lines with membranes inthe end connectors to retain fluid within the respective connect line,and wherein the one-time quick connect ports and the one-time quickconnect lines connect such that the membranes within the end connectorsrupture.
 31. The vehicle of claim 29, wherein the quick connect inletport and the quick connect outlet port of the exterior subsystem and thequick connect inlet port and the quick connect outlet port of theinterior subsystem are low loss quick connect ports, wherein the firstand second quick connect lines are low loss quick connect lines, andwherein the low loss quick connect ports and the low loss quick connectlines removably connect so that connection and disconnection can takeplace multiple times with low loss of refrigerant fluid.
 32. The vehicleof claim 23, wherein the driver compartment is at least partiallysegregated from the sleeper compartment.
 33. An air conditioning systemfor use in an over-the-road vehicle, comprising: a variable-speedcompressor for providing refrigerant to a heat exchanger positioned toprovide temperature control to an interior compartment of a vehicle; abrushless DC motor operably coupled to the variable-speed compressor; anevaporator; and an controller operably coupled to the motor, wherein thecontroller receives electric power from at least one source of electricpower operable when an engine of the vehicle is not operating; andwherein the controller modulates compressor speed of the compressor suchthat the evaporator is maintained at a predetermined evaporatortemperature.